The Brain!Child Development

Georgia CTAE Resource Network Instructional Resources Office

July 2009

Glial Cells are cells in the brain that primarily support and nourish neurons.

Neurons are nerve cells in the brain that are primarily responsible for transporting information.

Axons are the sender – the long ending of a neuron that sends information.

The protective coating around an axon preventing short-circuiting between neurons is called the myelin sheath.

Dendrites (the receiver) are short nerve projections from the cell body of the neuron that receive information.

Synapses are connecting places where chemical information is delivered by the axon of a neuron and received by dendrites of another neuron.

Serotonin is the neurotransmitter carrying coded information regulating the onset of sleep.

Is oblong in shape and weighs about 3 pounds. It takes up about half of the volume of your head. It has the appearance of a pinkish gray wrinkled walnut, smells like blue cheese, and feels soft and slimy like gelatin. The brain is the commander in chief of everything your body does twenty-four hours a day.

Before birth, a baby’s neurons increase in number at an astonishing rate increasing the size of the brain. They are not fully equipped, properly positioned, or completely functioning.

30,000 neurons would fit in the space the size of a pinhead.

At birth, the brain’s cerebral cortex has 100 billion neurons; but few neurons are connected.

After birth, neurons are not created. The increase in brain size is due to an increase in the size of neurons and the number of connections they make through axon growth and dendrite branching.

Experience creates neuron connections. Each neuron can make between 5,000 and 50,000 connections with other neurons.

By age three, 1,000 trillion connections exist…twice as many as adults have.

Connections used repeatedly become permanent. Those that are seldom or never used get pruned or “weeded out.”